ASTM B594-19e1

Standard Practice for Ultrasonic Inspection of Aluminum-Alloy Wrought Products

SIGNIFICANCE AND USE
5.1 A number of factors such as the condition of the entry and back surfaces of the inspected part, the inclination of the ultrasonic beam with respect to the entry surface, and variations in the performance characteristics of the test system may cause significant differences in amplitudes of discontinuity indications and back reflections. These factors can seriously impair the reliability and the quantitative value of the ultrasonic test outlined in this practice.  
5.2 Accurate evaluations of discontinuity size are also significantly affected by variations in search unit characteristics and by irregularities in discontinuity surfaces which can influence reflectivity. For these reasons, the discontinuity sizes that may be implied by the ultrasonic comparisons outlined in this practice must be regarded as “apparent” or “estimated” in recognition of the limited quantitative value of the measurement.  
5.3 Because numerous interacting variables in a test system can adversely influence the results of an ultrasonic inspection, the actual quantitative effects of detected discontinuities upon the mechanical properties of the inspected product are difficult to establish. Although this practice provides a reliable control of product quality during manufacture, it is not applicable as an exclusive indicator of the ultimate quality and performance of components fabricated from the inspected products covered by this practice.
SCOPE
1.1 This practice covers the requirements for pulse-echo ultrasonic inspection and includes criteria used to define applicable quality levels of aluminum-alloy wrought products when performance of the ultrasonic test by the producer is specified, or when ultrasonic inspection is performed by the purchaser upon receipt.  
1.2 This practice is not applicable if plastic deformation is introduced into the material after delivery.  
1.3 The ultrasonic test described in this practice is employed to detect internal discontinuities oriented in a direction parallel to, or nearly parallel to, the surface of the product. The test is performed either by the immersion method or the contact method using pulsed longitudinal waves which are transmitted and received by a search unit containing either a single crystal or a combination of electrically interconnected multiple crystals. Ultrasonic tests employing either the through-transmission or the angle-beam techniques are not included.  
Note 1: Ultrasonic tests employing angle-beam techniques require special reference blocks, search units, and scanning procedures and are subject to negotiation between the purchaser and the seller when such tests are required by the contract or purchase order.  
1.4 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units which are provided for information only and are not considered standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2019
• ICS: 77.040.20 - Non-destructive testing of metals
• ICS: 77.120.10 - Aluminium and aluminium alloys
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.06 - Ultrasonic Method

Relations

• Refers: ASTM B881-17 - Standard Terminology Relating to Aluminum- and Magnesium-Alloy Products
• Effective Date: 01-Nov-2017
• Refers: ASTM E317-11 - Standard Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-Echo Testing Instruments and Systems without the Use of Electronic Measurement Instruments
• Effective Date: 01-Aug-2011
• Refers: ASTM E114-10 - Standard Practice for Ultrasonic Pulse-Echo Straight-Beam Contact Testing
• Effective Date: 15-Jun-2010
• Refers: ASTM E127-10 - Standard Practice for Fabricating and Checking Aluminum Alloy Ultrasonic Standard Reference Blocks
• Effective Date: 15-Feb-2010
• Refers: ASTM B881-09 - Standard Terminology Relating to Aluminum- and Magnesium- Alloy Products
• Effective Date: 01-Jun-2009
• Refers: ASTM E127-07 - Standard Practice for Fabricating and Checking Aluminum Alloy Ultrasonic Standard Reference Blocks
• Effective Date: 01-Dec-2007
• Refers: ASTM E317-06a - Standard Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-Echo Testing Instruments and Systems without the Use of Electronic Measurement Instruments
• Effective Date: 01-Dec-2006
• Refers: ASTM E127-06 - Standard Practice for Fabricating and Checking Aluminum Alloy Ultrasonic Standard Reference Blocks
• Effective Date: 01-May-2006
• Refers: ASTM E317-06 - Standard Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-Echo Testing Instruments and Systems without the Use of Electronic Measurement Instruments
• Effective Date: 01-May-2006
• Refers: ASTM E114-95(2005) - Standard Practice for Ultrasonic Pulse-Echo Straight-Beam Examination by the Contact Method
• Effective Date: 01-Dec-2005
• Refers: ASTM B881-05 - Standard Terminology Relating to Aluminum- and Magnesium- Alloy Products
• Effective Date: 01-Sep-2005
• Refers: ASTM E127-05 - Standard Practice for Fabricating and Checking Aluminum Alloy Ultrasonic Standard Reference Blocks
• Effective Date: 01-Apr-2005
• Refers: ASTM E127-04 - Standard Practice for Fabricating and Checking Aluminum Alloy Ultrasonic Standard Reference Blocks
• Effective Date: 01-Jul-2004
• Refers: ASTM B881-98a(2004) - Standard Terminology Relating to Aluminum- and Magnesium- Alloy Products
• Effective Date: 01-Apr-2004
• Refers: ASTM E214-68(1996) - Standard Practice for Immersed Ultrasonic Examination by the Reflection Method Using Pulsed Longitudinal Waves
• Effective Date: 10-Mar-2001

Overview

ASTM B594-19e1 establishes standardized procedures for the ultrasonic inspection of aluminum-alloy wrought products. Developed by ASTM International, this standard practice covers the use of pulse-echo ultrasonic methods-either by contact or immersion-to detect internal discontinuities within aluminum alloy materials. These inspection techniques help ensure the quality of aluminum products by identifying flaws parallel or nearly parallel to the product surface before further manufacturing or assembly processes. However, ultrasonic inspection according to this standard is not intended for use after plastic deformation is introduced to the material.

Key Topics

• Inspection Scope: Focuses on pulse-echo ultrasonic testing for internal discontinuities in aluminum-alloy wrought products, employing either immersion or direct contact methods with straight-beam, longitudinal wave transducers.
• Discontinuity Types: Ideal for detecting flaws aligned parallel to the product surface; angle-beam and through-transmission ultrasonic techniques are excluded.
• Apparatus Requirements: Test equipment must meet specific guidelines for sensitivity, resolution, and scanning consistency to ensure reliable ultrasonic results.
• Quality Levels: Defines acceptance and rejection criteria, including class-based limits for the size and grouping of detected discontinuities.
• Limitations: Measurement values are described as "apparent" or "estimated" due to various influencing factors such as surface condition, search unit characteristics, and system variability. The test is a reliable process control measure during manufacture but not a comprehensive assessment of finished part performance.
• Surface and Environmental Considerations: Entry and back surfaces must be clean, smooth, and flat. Testing should be performed under controlled temperature and environmental conditions.
• Personnel Qualification: Operators must be properly qualified and certified under relevant industry standards for nondestructive testing.

Applications

The ASTM B594-19e1 standard is widely used in industries where the reliability and performance of aluminum-alloy wrought products are critical, including aerospace, defense, automotive, and construction. Specific use cases include:

• Quality Control in Manufacturing: Applying ultrasonic inspection procedures at the production stage to detect subsurface defects before the products are shipped or subjected to additional processing.
• Purchaser Verification: Customers may perform ultrasonic testing upon receipt to confirm material integrity and compliance with specified quality levels.
• Process Optimization: Manufacturers use the standard to monitor and control product quality, minimizing the risk of internal defects that could affect end-use performance.
• Documentation and Compliance: Provides a recognized methodology for specifying acceptance limits and test procedures in contracts and purchasing agreements for aluminum-alloy wrought goods.

Related Standards

Compliance with ASTM B594-19e1 is supported by reference to several associated standards and practices:

• ASTM E114: Practice for Ultrasonic Pulse-Echo Straight-Beam Contact Testing
• ASTM E127: Practice for Fabrication and Control of Flat Bottomed Hole Ultrasonic Standard Reference Blocks
• ASTM E317: Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-Echo Testing Instruments
• ASTM B881: Terminology Relating to Aluminum- and Magnesium-Alloy Products
• ASNT SNT-TC-1A: Personnel Qualification and Certification in Nondestructive Testing
• NAS-410: Certification of Inspection Personnel

These related standards enhance the consistency, reliability, and comparability of nondestructive ultrasonic inspection across the aluminum industry.

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Keywords: ASTM B594, ultrasonic inspection, aluminum-alloy wrought products, nondestructive testing, pulse-echo, internal discontinuities, quality control, standard practice, immersion method, contact method, acceptance criteria, manufacturing standards.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
´1
Designation: B594 − 19
Standard Practice for
Ultrasonic Inspection of Aluminum-Alloy Wrought Products
This standard is issued under the fixed designation B594; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—Editorial corrections were made to Fig. 4 and Note 14 in April 2021.
1. Scope* ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This practice covers the requirements for pulse-echo
mendations issued by the World Trade Organization Technical
ultrasonic inspection and includes criteria used to define
Barriers to Trade (TBT) Committee.
applicable quality levels of aluminum-alloy wrought products
when performance of the ultrasonic test by the producer is
2. Referenced Documents
specified, or when ultrasonic inspection is performed by the
2.1 The following documents of the issue in effect on date
purchaser upon receipt.
of material purchase form a part of this practice to the extent
1.2 This practice is not applicable if plastic deformation is
referenced herein:
introduced into the material after delivery.
2.2 ASTM Standards:
1.3 Theultrasonictestdescribedinthispracticeisemployed
B881 Terminology Relating toAluminum- and Magnesium-
to detect internal discontinuities oriented in a direction parallel
Alloy Products
to, or nearly parallel to, the surface of the product. The test is
E114 Practice for Ultrasonic Pulse-Echo Straight-Beam
performed either by the immersion method or the contact
Contact Testing
method using pulsed longitudinal waves which are transmitted
E127 Practice for Fabrication and Control of Flat Bottomed
and received by a search unit containing either a single crystal
Hole Ultrasonic Standard Reference Blocks
or a combination of electrically interconnected multiple crys-
E214 Practice for Immersed Ultrasonic Testing by the Re-
tals.Ultrasonictestsemployingeitherthethrough-transmission
flection Method Using Pulsed Longitudinal Waves (With-
or the angle-beam techniques are not included.
drawn 2007)
E317 Practice for Evaluating Performance Characteristics of
NOTE 1—Ultrasonic tests employing angle-beam techniques require
Ultrasonic Pulse-Echo Testing Instruments and Systems
special reference blocks, search units, and scanning procedures and are
subjecttonegotiationbetweenthepurchaserandthesellerwhensuchtests
without the Use of Electronic Measurement Instruments
are required by the contract or purchase order.
2.3 American Society for Nondestructive Testing Standard:
1.4 The values stated in inch-pound units are to be regarded
ASNT Recommended Practice for Nondestructive Testing
asthestandard.Thevaluesgiveninparenthesesaremathemati- Personnel Qualification and Certification—Ultrasonic
cal conversions to SI units which are provided for information
Testing Method, SNT-TC-1A
only and are not considered standard. 2.4 National Aerospace Standard:
NAS-410 Certification of Inspection Personnel
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions—Refer to Terminology B881 for definitions
priate safety, health, and environmental practices and deter-
of product terms used in this practice.
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dance with internationally recognized principles on standard-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
1 3
This practice is under the jurisdiction of ASTM Committee E07 on Nonde- The last approved version of this historical standard is referenced on
structive Testing and is the direct responsibility of Subcommittee E07.06 on www.astm.org.
Ultrasonic Method. AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box
Current edition approved May 1, 2019. Published June 2019. Originally 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
approved in 1974. Last previous edition approved in 2013 as B594 – 13. DOI: Available fromAerospace IndustriesAssociation ofAmerica, Inc. (AIA), 1000
10.1520/B0594-19E01. WilsonBlvd.,Suite1700,Arlington,VA22209-3928,http://www.aia-aerospace.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
B594 − 19
4. Summary of Practice 6.1.2 Engineering Drawings—When ultrasonic inspection
is specified for alloys, section thicknesses, and weights outside
4.1 The product is inspected ultrasonically by scanning
limits established in applicable product specifications, the
specified entry surfaces with a beam of pulsed longitudinal
specialdiscontinuityclasslimitsshallbeasnegotiatedbetween
waves oriented in a direction perpendicular to the entry
the purchaser and the producer and shall be indicated on zoned
surface.Theultrasoundistransmittedintotheproducteitherby
engineering drawings describing the material to be inspected
the direct contact or the immersion method. During the scan,
on part machine drawings. The drawings shall also indicate
indications representing discontinuities are displayed on an
non-critical areas on the material and areas that will be
A-scan screen of the test instrument and may be detected by
removed by machining.
auxiliary electronic monitors, if used.
6.1.3 Special Testing Procedures—Cylindrical sections or
4.2 When the test system sensitivity level is appropriately
specifiedareasofpartscontainingfilletsmayrequireadditional
adjusted, detected discontinuities and variations in back reflec-
inspections employing special ultrasonic testing procedures
tion patterns are evaluated by comparing amplitudes of indi-
(for example, angle-beam, shear-wave technique) not covered
cations with the ultrasonic responses from selected ultrasonic
by this practice. Such special testing procedures and accep-
standard reference blocks. The evaluated ultrasonic disconti-
tance limits shall be established by negotiation and agreement
nuity responses are then classified and compared with appli-
between the purchaser and producer.
cable acceptance criteria.
7. Apparatus
NOTE 2—Additional information describing ultrasonic tests by the
direct contact method and by the immersion method is available in
7.1 The required ultrasonic test system shall consist of the
Practices E114 and E214.
following:
7.1.1 Basic Test Instrument—Any electronic device that
5. Significance and Use
produces electrical pulses to activate a search unit and displays
5.1 A number of factors such as the condition of the entry
pulses representing ultrasonic reflections on an A-scan screen
and back surfaces of the inspected part, the inclination of the
is satisfactory if the minimum performance characteristics
ultrasonic beam with respect to the entry surface, and varia-
specified in 7.1.3 are met. The instrument shall provide stable
tions in the performance characteristics of the test system may
linear amplification of received pulses at a selected test
cause significant differences in amplitudes of discontinuity
frequency and required sensitivity levels within the specified
indications and back reflections. These factors can seriously
minimum performance limits.
impair the reliability and the quantitative value of the ultra-
7.1.2 Search Unit—The recommended search unit is the flat
sonic test outlined in this practice.
nonfocusing type and contains a piezoelectric crystal which
5.2 Accurate evaluations of discontinuity size are also
generates and receives longitudinal waves at the rated fre-
significantlyaffectedbyvariationsinsearchunitcharacteristics
quency when connected to the test instrument through a
and by irregularities in discontinuity surfaces which can
suitable coaxial cable. A dual-crystal search unit containing
influence reflectivity. For these reasons, the discontinuity sizes
bothatransmittingandareceivingcrystalinonecontainermay
that may be implied by the ultrasonic comparisons outlined in
be used provided the test instrument will accommodate two-
this practice must be regarded as “apparent” or “estimated” in
crystaloperation.Specialtestsemployingfocusingsearchunits
recognition of the limited quantitative value of the measure-
may be used provided such tests are established by negotiation
ment.
and agreement between purchaser and producer.
5.3 Because numerous interacting variables in a test system 7.1.2.1 Search Unit Size—Any search unit of either circular
or rectangular configuration may be used for initial scanning.
can adversely influence the results of an ultrasonic inspection,
the actual quantitative effects of detected discontinuities upon For a circular configuration that provides an effective crystal
2 2
area greater than 1.00 in. (6.45 cm ) and for all rectangular
the mechanical properties of the inspected product are difficult
to establish. Although this practice provides a reliable control search units a documented method of providing a uniform
entry surface for the full extent of the sound beam shall be
ofproductqualityduringmanufacture,itisnotapplicableasan
agreed upon between the purchaser and producer.Asearch unit
exclusive indicator of the ultimate quality and performance of
containing a circular crystal of an effective diameter no greater
components fabricated from the inspected products covered by
than 0.75 in. (19.0 mm) is required to evaluate the ultrasonic
this practice.
response from detected discontinuities. When connected to the
6. Special Requirements test instrument and used for initial scanning and evaluating
responses from discontinuities, the search unit shall meet or
6.1 When ultrasonic inspection of the finished product is
exceed the required minimum performance characteristics at
required of the producer, purchase orders or contracts shall
the selected test frequency. Search units used only for initial
include the following information:
scanning of a part prior to evaluation of suspect discontinuities
6.1.1 SpecialAcceptance Limits—Discontinuityclasslimits,
shall, as a minimum, have adequate performance of sensitivity
if other than those defined in Section 11, shall be subject to
and signal to noise ratio appropriate to the class of inspection
negotiation between the purchaser and the producer and shall
described in Section 11.
be in accordance with an agreement established between the
purchaser and the producer at the time of quotation or
NOTE 3—The same search unit used for initial scanning may also be
acceptance of purchase order or contract. used for evaluating discontinuities provided its effective crystal diameter
´1
B594 − 19
is no greater than 0.75 in. (19.0 mm) and minimum test system
adjusted to obtain a hole indication that is equal to 80 % of the
performance requirements are satisfied. Rectangular search units may be
vertical limit. The effective beam width shall be the traverse
used for evaluation if the method of use is established in writing by the
distance in the index direction over which the indication from
producer and approved by the purchaser.
the flat-bottom hole equals or exceeds 40 % of the vertical
(a) Phased Array Transducers: Linear Arrays—Virtual
limit. The effective beam width establishes the maximum
probes within the array shall meet the requirements for
allowable index distance used during the initial scan sensitivity
minimum effective beam width of 7.1.2.2 in both the scan and
for each inspection.
index directions. Each virtual probe in the array shall meet the
applicable requirements of a conventional probe as defined in 7.1.2.3 Distance-Amplitude Characteristics—The distance-
7.1.2.1. There shall be no more than one dead element in a amplitude characteristics shall be established and recorded for
virtual probe and the array shall not have two adjacent dead each search unit by obtaining the ultrasonic response from a
elements. Virtual probe responses in the array shall be normal- complete distance-amplitude set of ultrasonic standard refer-
ized to each other at one or more metal travel depths periodi-
ence blocks containing the No. 5 (0.078-in. diameter (1.98-mm
cally. All virtual probes in the array shall have an amplitude diameter))flat-bottomedholes(see7.4)atanominalsensitivity
response within 15 % of the mean amplitude.
level to be used for evaluating the estimated size of detected
NOTE4—Othernon-lineararraysmeetingtherequirementsin7.1.2.1(a)
discontinuities. When using the search unit during testing, a
may be used on agreement between the purchaser and producer.
check of the established distance-amplitude characteristics
7.1.2.2 Effective Beam Width—The effective beam width of
shall be conducted at least once per 8-h shift and shall be
the search unit shall be established by determining the total
performed by noting the ultrasonic response from at least three
traverse distance over which response is maintained within
selected No. 5 distance-amplitude reference blocks at the
limits specified below. The hole size in the standard Practice
established sensitivity level. If the response from any block
E127referenceblocktobeusedfordeterminingeffectivebeam
differs by more than 610 % of the original distance-amplitude
width shall be in accordance with those listed in Table 1 for the
curve established for the selected search unit, the performance
applicable class of inspection. The metal distance of the
of the search unit shall be reevaluated and the test system shall
reference block shall be that which produces the smallest
be restandardized to ensure proper conformance to the require-
clearly resolved hole indication. The same water distance to be
ments in this practice, and all metal tested since the previous
used for scanning shall be used to determine effective beam
standardization shall be retested.
width.
When testing metal to requirements that necessitate ultra-
(a) For round search units, a maximum indication shall be
sonic reference standards other than No. 5 reference standards
obtained from the hole and then the instrument gain control
for inspection and/or evaluation (i.e., classAAA,AA,A, B, or
shall be adjusted to obtain a hole indication that is equal to
C), it is acceptable to offset the distance amplitude curve by a
80 %oftheverticallimit.Theeffectivebeamwidthshallbethe
built-in or internally connected attenuator calibrated in deci-
traverse distance in the index direction over which the indica-
bels. Attenuators must affect only the return ultrasonic signal.
tion from the flat-bottom hole equals or exceeds 40 % of the
Correction factors to be used after standardization on No. 5
vertical limit.
ultrasonic reference standards are shown in Table 2.
(b) For rectangular search units, an indication shall be
obtained from the hole at any point along the longitudinal axis
NOTE 5—The distance amplitude curve may be established on one or
of the search unit and then the instrument gain control shall be more sets of ultrasonic standard reference blocks, containing other than
TABLE 1 Ultrasonic Classes
Single Discontinuity Linear Discontinuity
Multiple Discontinuities Loss of Back Reflection Noise
Class Response Length–Response
C,B E F
in. (mm) (%) in. (mm)
A,B D
in. (mm) in. (mm)
AAA ⁄64 (0.40) or 25 % of 10 % of 0.12 (3.0)–10 % of 50 10 % of
3 3 3 3
⁄64 (1.19) response ⁄64 (1.19) response ⁄64 (1.19) response ⁄64 (1.19) response
3 2 2
AA ⁄64 (1.19) ⁄64 (0.79) 0.5 (12.7)– ⁄64 (0.79) response 50 alarm level
5 3 3
A ⁄64 (1.98) ⁄64 (1.19) 1.0 (25.4)– ⁄64 (1.19) response 50 alarm level
8 5 5
B ⁄64 (3.18) ⁄64 (1.98) 1.0 (25.4)– ⁄64 (1.98) 50 alarm level
C ⁄64 (3.18) Not applicable Not applicable 50 alarm level
A
Any discontinuity with an indication greater than the response from a reference flat-bottom hole or equivalent notch at the estimated discontinuity depth of the size given
(inches diameter) is not acceptable.
B 1 2
NIST certified blocks are not available for ⁄64 in. (0.40 mm) and ⁄64 in. (0.79 mm) hole diameters. The following substitutions and correction factors are approximations
based on the area-amplitude relationships and shall be applied as follows:
3 1
A ⁄64 in. hole reference block may be substituted for a ⁄64 in. hole reference block by using a correction factor of 19 dB.
3 2
A ⁄64 in. hole reference block may be substituted for a ⁄64 in. hole reference block by using a correction factor of 7 dB.
C
Multiple discontinuities with indications greater than the response from a reference flat-bottom hole at the estimated discontinuity depth of the size given (inches diameter)
are not acceptable if the centers of any two of these discontinuities are less than 1.0 in. apart. Not applicable to class C.
D
Any discontinuity longer than the length given with maximum indications greater than the response given (flat-bottom hole or equivalent notch response) is not
acceptable. Not applicable to class C.
E
Loss of back reflection greater than the percent given, when compared to non-defective material in a similar or like part, is not acceptable when this loss of back reflection
is accompanied by an increase in noise signal (at least double the normal background noise signal) between the front and back surface. Applicable only to straight beam
tests.
F
Noise which exceeds the alarm level setting is not acceptable, except for re-forging stock.
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B594 − 19
TABLE 2 Ultrasonic Reference Hole Correction Factors
7.2.2.1 Manipulator and Bridge—When a manipulator is
Ultrasonic Reference Correction Factor Percentage of No. 5 used in tests by the immersion method, the manipulator shall
Hole inch (mm) from No. 5 Reference Hole Hole Signal Amplitude
adequately support a search tube containing a search unit and
1/64 (0.40) –28 dB 4%
shall provide fine adjustment of angle within 1° in two vertical
2/64 (0.79) –16 dB 16%
3/64 (1.19) –9 dB 36% planes that are perpendicular to each other. The bridge shall be
5/64 (1.98) 0 dB 100%
of sufficient strength to provide rigid support for the manipu-
8/64 (3.18) +8 dB 256%
lator and shall allow smooth, accurate positioning of the search
unit within 60.05 in. (61.3 mm). During the inspection
procedure, the scanning apparatus shall permit measurement of
No.5flatbottomedholes,whenjustifiedbytheinspectionclassofSection
both the scan distance and the index distance within 60.1 in.
11.
(62.5 mm).
NOTE 6—This section is not applicable when using the alternative
7.2.2.2 Special Fixtures—Special search unit-supporting
procedure allowed by 10.5.2.
fixtures such as bubblers and wheel search units may be used
7.1.2.4 Uniformity of Response for Rectangular Search
provided they meet the requirements prescribed for a manipu-
Units—Rectangular search units shall exhibit beam uniformity
lator and bridge and provided the test results obtained with
within 610 % of the mean amplitude of indication from the
special fixtures are equivalent to those obtained by the immer-
flat-bottomed hole during a traverse along the longitudinal axis
sion method.
of the search unit at the scanning sensitivity established with
7.2.2.3 Contact Scanning Unit—During tests by the contact
reference blocks for the applicable class (exclusive of end lobe
method, the search unit usually is supported and positioned
responses).
manually on the entry surface of the inspected product.
7.1.3 Test System Performance—When used with appropri-
However, special fixtures for contact scanning may be em-
ate auxiliary equipment described in subsequent paragraphs,
ployed provided their use ensures conformance to the require-
the test system shall be capable of meeting or exceeding the
ments in this practice.
minimum performance characteristics listed in Table 3 as
7.2.2.4 Manual Immersion Scanning—When part size or
determined by procedures outlined in Practice E317. If instru-
geometry, or both, prevent the use of manipulating equipment,
ment A-scan display dimensions exceed the 2.5-in. (63.5-mm)
transducer stand-off attachments which provide for the control
vertical limit and the 3.5-in. (88.9-mm) horizontal limit, the
of water travel distance and sound beam angle shall be used.
instrument shall be considered usable throughout the entire
Provisions shall be made to ascertain that wear of stand-off
A-scan screen height or width found to be linear with the
attachments do not exceed limits which will degrade the test.
procedures prescribed in Practice E317. All other minimum
7.3 Couplant—Clean water at room temperature (see 9.3),
characteristics listed in Table 3 remain applicable.
free of visible air bubbles that could interfere with the test, is
7.2 Auxiliary Equipment—In addition to the ultrasonic test
the recommended couplant for tests by the immersion method.
system previously described, the following equipment is nec-
Inhibitors or wetting agents, or both, may be used. For tests by
essary:
the contact method, the recommended couplant is clean,
7.2.1 Tank—For tests by the immersion method, any con-
light-grade oil.
tainer is satisfactory that will facilitate the accurate, stable
NOTE 7—Other coupling liquids may be employed provided their use
positioning of both the search unit and the product to be
does not adversely affect either the test results or the product.
inspected.
7.2.2 Scanning Apparatus—The search unit shall be sup- 7.4 Reference Standards—The ultrasonic reference stan-
ported by any one of the following devices: dards required for the inspection of aluminum-alloy products
TABLE 3 Minimum Performance Characteristics Required for Ultrasonic Test Systems
NOTE 1—The minimum requirements shown in this table are applicable as indicated only for the selected frequencies used for the inspection. The test
system is required to meet the limits only for the test frequencies actually used.
Test Frequency, MHz
Performance Characteristics
2.25 5.0 10.0 15.0
Vertical limit, in. (mm), min 2.5 (63.5) 2.5 (63.5) 2.5 (63.5) 2.5 (63.5)
A
Upper linearity limit, min 95 95 95 95
A
Lower linearity limit, max 10 10 10 10
A,B
Ultrasonic sensitivity, min 50 100 80 50
B,C
Signal-to-noise ratio, min 10:1 10:1 10:1 10:1
Entry surface resolution, in. (mm) of aluminum, max 0.7 (18) 0.5 (13) 0.3 (8) 0.2 (5)
Back surface resolution, in. (mm) of aluminum, max 0.3 (8) 0.2 (5) 0.1 (3) 0.1 (3)
Horizontal limit, in. (mm), min 3.5 (89) 3.5 (89) 3.5 (89) 3.5 (89)
D
Horizontal linearity, min 85 85 85 85
A
% of vertical limit.
B
For ultrasonic inspections performing to Class AAA, use ASTM reference block 1–0300.
For ultrasonic inspections performing to Class AA, use ASTM reference block 2–0300.
For ultrasonic inspections performing to Class A through C, use ASTM reference block 3–0300.
C
Applies to the electrical component.
D
% of horizontal limit.
´1
B594 − 19
TABLE 4 Allowable Response Height as a Function of the
shall be a distance-amplitude set of aluminum-alloy ultrasonic
Attenuator/Decade Switch Position
standard reference blocks fabricated and checked in accor-
Decade or Attenuator Switch Positions
dance with Practice E127.
0.1X 1X 10X
10 dB 30 dB 50 dB
NOTE 8—When side-wall reflections caused by sound-beam divergence
prevents the use of Practice E127 reference blocks, special blocks of the
Allowable range for 10→90–100 or saturated
same material as used in Practice E127 blocks may be used. A-scan response 10→90–100 or saturated
height, percent 6–13←95
7.4.1 The distance-amplitude set shall consist of the appro-
6–13←95
→
priate number of groups, as defined by the applicable Class, of
←
Practice E127 reference blocks (see Table 1). Discontinuity
Switch direction
indications shall be compared with the response having the
same metal distance within 6 ⁄8 in. (63.2 mm) for metal
distances from ⁄4 in. (6.4 mm) through 1.0 in. (25.4 mm),
within 6 ⁄4in.formetaldistancesfromover1.0in.through3.0
in. (76.2 mm), and within 6 ⁄2 in. (612.7 mm) for metal
distances over 3.0 in. The above requirements can be met
optionally with blocks having the hole sizes specified in Table
1 and either of the following sets of metal distances:
in. (mm) in. (mm)
0.25 (6.4) 0.25 (6.4)
0.50 (12.7) 0.37 (9.4)
0.75 (19.0) 0.62 (15.7)
FIG. 1 A-scan Displays Corresponding to Decade Switch Multi-
1.00 (25.4) 0.87 (22.1)
plier Check
1.50 (38.1) 1.25 (31.8)
2.00 (50.8) 1.75 (44.4)
2.50 (63.5) 2.
...